Cetane-improving component for diesel fuels and diesel fuels containing it

Diesel fuel characterized in that it comprises:

• at least one hydrocarbon from distillates with a boiling point varying from 180 to 350° C.,
• at least one component comprising at least one stearic ester chosen from the esters of linear or branched monoalcohols containing 1 to 6 carbon atoms:
• a) in pure state, in a mixture with at least one ester of an unsaturated linear fatty acid having at least 18 carbon atoms,
• b) in pure state, added to a mixture of at least one ester of a vegetable or animal oil in crude or partially hydrogenated form,
• c) or included in a mixture of one or more esters of vegetable and/or animal oils in crude or partially hydrogenated form,
• the mixtures of saturated and unsaturated esters being such that the ratio by mass of the level of stearic ester(s) to the sum of the levels of unsaturated fatty acid esters present in the esters of animal or vegetable oils varies from 1 to 12%, the unsaturated fatty acid esters being esters of unsaturated mono- or polyacids containing at least 18 carbon atoms, and esters of monoalcohols, and
• the stearic acid ester level in said fuel being between 0.5 and 2.4% by mass.